playManifest beacon non-base64 encoded referrers
playManifest beacon non-base64 encoded referrers

some apps are not base64-encoding the referrer, detect it by -
1. running base64_decode in strict mode
2. checking whether the result is valid utf8
when this happens, send the referrer as is on the beacon (without
b64decode)

kaltura/server,kaltura/server,kaltura/server,kaltura/server,kaltura/server,kaltura/server